/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.scenes.scene2d.ui;

import static com.badlogic.gdx.scenes.scene2d.actions.Actions.*;

import com.badlogic.gdx.Input.Keys;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.Interpolation;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.Group;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.InputListener;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.actions.Actions;
import com.badlogic.gdx.scenes.scene2d.ui.Label.LabelStyle;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton.TextButtonStyle;
import com.badlogic.gdx.scenes.scene2d.utils.Align;
import com.badlogic.gdx.scenes.scene2d.utils.ChangeListener;
import com.badlogic.gdx.scenes.scene2d.utils.FocusListener;
import com.badlogic.gdx.scenes.scene2d.utils.FocusListener.FocusEvent;
import com.badlogic.gdx.utils.ObjectMap;

/** Displays a dialog, which is a modal window containing a content table with a button table underneath it. Methods are provided
 * to add a label to the content table and buttons to the button table, but any widgets can be added. When a button is clicked,
 * {@link #result(Object)} is called and the dialog is removed from the stage.
 * @author Nathan Sweet */
public class Dialog extends Window {
	/** The time in seconds that dialogs will fade in and out. Set to zero to disable fading. */
	static public float fadeDuration = 0.4f;

	Table contentTable, buttonTable;
	private Skin skin;
	ObjectMap<Actor, Object> values = new ObjectMap();
	boolean cancelHide;
	Actor previousKeyboardFocus, previousScrollFocus;

	public Dialog (String title, Skin skin) {
		super(title, skin.get(WindowStyle.class));
		this.skin = skin;
		initialize();
	}

	public Dialog (String title, Skin skin, String windowStyleName) {
		super(title, skin.get(windowStyleName, WindowStyle.class));
		this.skin = skin;
		initialize();
	}

	public Dialog (String title, WindowStyle windowStyle) {
		super(title, windowStyle);
		initialize();
	}

	private void initialize () {
		setModal(true);

		defaults().space(6);
		add(contentTable = new Table(skin)).expand().fill();
		row();
		add(buttonTable = new Table(skin));

		contentTable.defaults().space(6);
		buttonTable.defaults().space(6);

		buttonTable.addListener(new ChangeListener() {
			public void changed (ChangeEvent event, Actor actor) {
				while (actor.getParent() != buttonTable)
					actor = actor.getParent();
				result(values.get(actor));
				if (!cancelHide) hide();
				cancelHide = false;
			}
		});

		addListener(new FocusListener() {
			public void keyboardFocusChanged (FocusEvent event, Actor actor, boolean focused) {
				if (!focused) focusChanged(event);
			}

			public void scrollFocusChanged (FocusEvent event, Actor actor, boolean focused) {
				if (!focused) focusChanged(event);
			}

			private void focusChanged (FocusEvent event) {
				Stage stage = getStage();
				if (isModal && stage != null && stage.getRoot().getChildren().peek() == Dialog.this) { // Dialog is top most actor.
					Actor newFocusedActor = event.getRelatedActor();
					if (newFocusedActor == null || !newFocusedActor.isDescendantOf(Dialog.this)) event.cancel();
				}
			}
		});
	}

	public Table getContentTable () {
		return contentTable;
	}

	public Table getButtonTable () {
		return buttonTable;
	}

	/** Adds a label to the content table. The dialog must have been constructed with a skin to use this method. */
	public Dialog text (String text) {
		if (skin == null)
			throw new IllegalStateException("This method may only be used if the dialog was constructed with a Skin.");
		return text(text, skin.get(LabelStyle.class));
	}

	/** Adds a label to the content table. */
	public Dialog text (String text, LabelStyle labelStyle) {
		return text(new Label(text, labelStyle));
	}

	/** Adds the given Label to the content table */
	public Dialog text (Label label) {
		contentTable.add(label);
		return this;
	}

	/** Adds a text button to the button table. Null will be passed to {@link #result(Object)} if this button is clicked. The dialog
	 * must have been constructed with a skin to use this method. */
	public Dialog button (String text) {
		return button(text, null);
	}

	/** Adds a text button to the button table. The dialog must have been constructed with a skin to use this method.
	 * @param object The object that will be passed to {@link #result(Object)} if this button is clicked. May be null. */
	public Dialog button (String text, Object object) {
		if (skin == null)
			throw new IllegalStateException("This method may only be used if the dialog was constructed with a Skin.");
		return button(text, object, skin.get(TextButtonStyle.class));
	}

	/** Adds a text button to the button table.
	 * @param object The object that will be passed to {@link #result(Object)} if this button is clicked. May be null. */
	public Dialog button (String text, Object object, TextButtonStyle buttonStyle) {
		return button(new TextButton(text, buttonStyle), object);
	}

	/** Adds the given button to the button table. */
	public Dialog button (Button button) {
		return button(button, null);
	}

	/** Adds the given button to the button table.
	 * @param object The object that will be passed to {@link #result(Object)} if this button is clicked. May be null. */
	public Dialog button (Button button, Object object) {
		buttonTable.add(button);
		setObject(button, object);
		return this;
	}

	/** {@link #pack() Packs} the dialog and adds it to the stage, centered. */
	public Dialog show (Stage stage) {
		clearActions();
		previousKeyboardFocus = stage.getKeyboardFocus();
		previousScrollFocus = stage.getScrollFocus();
		pack();
		setPosition(Math.round((stage.getWidth() - getWidth()) / 2), Math.round((stage.getHeight() - getHeight()) / 2));
		stage.addActor(this);
		stage.setKeyboardFocus(this);
		stage.setScrollFocus(this);
		if (fadeDuration > 0) {
			getColor().a = 0;
			addAction(Actions.fadeIn(fadeDuration, Interpolation.fade));
		}
		return this;
	}

	/** Hides the dialog. Called automatically when a button is clicked. The default implementation fades out the dialog over
	 * {@link #fadeDuration} seconds and then removes it from the stage. */
	public void hide () {
		addAction(sequence(fadeOut(fadeDuration, Interpolation.fade), Actions.removeActor()));
	}

	protected void setParent (Group parent) {
		super.setParent(parent);
		if (parent == null) {
			Stage stage = getStage();
			if (stage != null) {
				Actor actor = stage.getKeyboardFocus();
				if (actor == this || actor == null) stage.setKeyboardFocus(previousKeyboardFocus);
				actor = stage.getScrollFocus();
				if (actor == this || actor == null) stage.setScrollFocus(previousScrollFocus);
			}
		}
	}

	public void setObject (Actor actor, Object object) {
		values.put(actor, object);
	}

	/** If this key is pressed, {@link #result(Object)} is called with the specified object.
	 * @see Keys */
	public Dialog key (final int keycode, final Object object) {
		addListener(new InputListener() {
			public boolean keyDown (InputEvent event, int keycode2) {
				if (keycode == keycode2) {
					result(object);
					if (!cancelHide) hide();
					cancelHide = false;
				}
				return false;
			}
		});
		return this;
	}

	/** Called when a button is clicked. The dialog will be hidden after this method returns unless {@link #cancel()} is called.
	 * @param object The object specified when the button was added. */
	protected void result (Object object) {
	}

	public void cancel () {
		cancelHide = true;
	}
}
